Rain gutters filled with soil. I wouldn't place them as high as the ones in this picture though. Maybe the height of a sawhorse. 
How do you keep the strawberries off the ground and away from bugs?
My wife and I used a hanging planter one year and that worked great but my wife can’t lift that sack of dirt and I’m not there to help in the garden.
She resorted to transplanting some of the berry plants to bowls and put them up on a retaining wall. She says the berries are coming in but the ants are having a field day.
Other than insecticide, what’s a good way to get a big sweet strawberry in the backyard?
Rain gutters filled with soil. I wouldn't place them as high as the ones in this picture though. Maybe the height of a sawhorse.
I have used straw with rosemary clippings added. For some reason, bugs hate the rosemary.
I mulch my strawberries with cardboard boxes covered with plain old pine straw.
Then I liberally sprinkle ‘sluggo plus’. So far, so good.
The solution to (fire) ants is, unfortunately, either the systemic pesticide applied somewhere OTHER than your strawberry bed (like all around it in a perimeter) OR finding the hills and using boiling water or some other physical solution.
I have one bed that keeps coming back in my strawberries. It’s a perennial problem. This year I’m going to replace that section of strawberries with a large (extra large) stepping stone. I haven’t even attempted to weed/thin that end of the bed yet. Hubby’s got to put the bad mojo on it this afternoon just so I can get in there.
I think the deep south is one giant fire ant bed with many many little entrances. I fear my whole house will disappear into a giant antbedsinkhole one day.
Since your strawberries are ‘up’ off the ground, you could sprinkle the broadcast ant poison along the wall itself.
Other than that I’m out of ideas too. If you live in the deep south the only fool proof way of dealing with fire ants involves, unfortunately, heavy weaponry. There aren’t any real indigenous counter measures for them. And they ‘evolve’ around those heavy weapons with unbelieveable speed.
I’ll end with this. Boiling water works. IF you’re VERY careful not to burn YOU AND the ants. My dad’s done it for years around his garden. He has a section of 1” or maybe a bit larger PVC pipe about 4ft long. He drilled about 1/4” holes liberally around the bottom 3ft of that. He tamps that into the mound as far as he can get it or 3ft whichever comes first, puts a great big funnel in it and pours gallons of boiling water into it. He’s also used other chemical means I won’t go into here. (Think ‘trench warfare’.) None of which are long lasting or systemic poisons. YMMV. MOST of the boiled mounds do NOT come back IF you can get a supply of ENOUGH boiling water at once.
I’m personally more scared of 3rd degree burns than I am of a small amount of broadcast ant poison. I’m clumsy that way. Just don’t walk barefoot near where you’ve put out the poison.
Now, all totally organic farmers who don’t live near fire ants can promptly expire from shock. One of my kids is allergic to them. At our house it’s a ‘stabbed or shot’ choice with ants/poison.